Yeah, I'm not doubting his ability or that it's passion driven. Bruno is pretty careful when it comes to making claims.
I'm not trying to paint Rob Watts as Jack Bybee or anything, just that the claim is pretty outlandish.
I take it no one has published any of their hearing tests yet?
Will you be first?
This guy is how old and talking about hearing stuff 130-150db down? Using his children watching cartoons as test data? I don’t know about you, but I said a lot of things that I wouldn’t consider reliable information while watching cartoons as a child.
I don’t care what their pedigree is, if it’s worth it’s salt then back up your claims with independently verifiable data- isn’t that the standard they’re held to in any other field they might occupy?
My bet is that no one who sells audio equipment that claims such amazing abilities of perception will ever publicly publish the results of a hearing test. Period. End of story.
And for good reason, as I believe they’d all likely show substantial hearing loss and abnormalities due to age, gender and abuse.
Please, I’d love for someone to prove me wrong.
I also believe that safely over 90% of this threads participants will have similar results.
They measure just about everything else humanly possible, to the limits of the most sophisticated available test equipment, yet refuse to test themselves?
Can “one of the best digital designers on the planet” not afford medical coverage, or is unable pay out of pocket for a hearing evaluation?
It takes less time than the car ride he took to that presentation. Costs less than a booth at an audio show, surely.
There’s no acceptable excuse.
It should be a required yearly disclosure for any audio reviewer.
If you say you can hear it; show me what you’re working with!!!
Would you trust a personal trainer with a gut hanging over his belt?
A dentist with no teeth?
I don’t think sensible consumers should accept anything less.
It’s disgusting to me that this field is not better regulated for consumer protection since it seems unable to self regulate. This lack of honesty has created a situation in which the majority of the world has a greater degree of trust in a used car salesman than an audio dealer.
Audio is not some kind of mystical alchemy learned in a remote cave by a talisman-wielding bearded wizard (unless that cave was a fortified cubicle at national and the bearded wizard was Bob Pease).
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I think these anecdotal stories are considered necessary, by their protagonists, to keep the high end audio business going on. No matter how much nonsense is said, like in this case, which would indicate abilities to hear a beetle moving in the green grass just below operating jet engine of B-707 and the tester standing few meters from that engine. However, a measure of nonsense in statements like this seems to be unlimited.
@spaceistheplace,
We have already been through what hearing standard hearing tests measure, likely not what you might be expecting. They measure the lowest SPL that one can hear different frequency bands. That's all. The most common compensation method to hear more frequencies is to turn up the volume level a little, exactly what Earl Geddes says he does.
The tests specifically do not measure ability to hear low percentages of distortion. Mostly that seems to be something people learn how to do with lots of practice over a prolonged period of time.
Also, could be that claimed numbers sound silly sometimes because numbers quoted may be for HD and what is mostly likely being heard with music is IMD at a much higher level.
EDIT: With some kinds of dacs, the situation can get even more complicated. State variables may settle giving very low HD numbers when steady test tones are used. With music, dynamic transients agitate state variables causing noise floor modulation which can be audible to some people. There may be other nonstationary nonlinearities with dacs as well.
We have already been through what hearing standard hearing tests measure, likely not what you might be expecting. They measure the lowest SPL that one can hear different frequency bands. That's all. The most common compensation method to hear more frequencies is to turn up the volume level a little, exactly what Earl Geddes says he does.
The tests specifically do not measure ability to hear low percentages of distortion. Mostly that seems to be something people learn how to do with lots of practice over a prolonged period of time.
Also, could be that claimed numbers sound silly sometimes because numbers quoted may be for HD and what is mostly likely being heard with music is IMD at a much higher level.
EDIT: With some kinds of dacs, the situation can get even more complicated. State variables may settle giving very low HD numbers when steady test tones are used. With music, dynamic transients agitate state variables causing noise floor modulation which can be audible to some people. There may be other nonstationary nonlinearities with dacs as well.
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Not the same thing at all. Stationary HD is what we measure. What we hear with music depends on the particular music, but the same nonlinearity that produces HD with a tone can produce much higher IMD distortion numbers with music, or with, say, a 32-tone IMD test.
In addition, for practiced listeners, correlated distortion may be more audible than an uncorrelated signal. Don't know why exactly. Presumably, brain DSP is better at picking up on it.
In addition, for practiced listeners, correlated distortion may be more audible than an uncorrelated signal. Don't know why exactly. Presumably, brain DSP is better at picking up on it.
If you take an original music file and send it through something with nonlinear distortion of -130dB and flat frequency response and make a (phase shift corrected) difference of the two files then, you will get a null, zero, inaudible signal. Nothing to be heard. Two same files. Call it "static" or "dynamic" nonlinearity, makes no difference.
It still exceeds the dynamic range of human hearing, this is pointless...
Are we trying hard enough yet to conjure up excuses to defend yet another crackpot theory that doesn't even hold up to the most basic scrutiny?
I am all for making the best measuring product you can, but the claims are crazy.
To clarify - do you think a DAC that produces THD @ -150 dB or whatever he claims at 1 kHz will do 50 or 60 dB worse in a multitone test? I'm not sure you'll find too many examples of that.
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Look, I don't know the limits of what some people may hear under all different conditions, nobody does. I agree that nobody is going to hear HD of a single fixed tone at -130dB.
However, sometimes there may be cases where HD is measured at a very low number and for unknown reasons, with music there is some small audible effect. Some people immediately conclude the only possible explanations are that someone is lying, or someone is imagining things.
My opinion is that sometimes there are things going on that are producing more audible effects than we are expecting from the measurements we make. IMD is one of the possibilities, but not the only one. We know there can also be what we may refer to as nonstationary nonlinearities. Thermal distortion would be one of those.
Some dacs, such as sigma-delta can have some very complex things going on in them that we rarely test for, that Stereophile does not test for either. Yet they exist. State variable settling can be one of those.
In addition to whatever some complex piece of electronics is doing, the human brain is also doing its thing. Sometimes the exact line between a perception that is real and that is imagined is very blurred and hard to pick apart. That we can see yellow from only green and blue is one effect that is pretty well understood and that most people experience so we think nothing of it. When only some people report an audible perceptual experience from a piece of complex electronics we may at first think they must be lying or crazy. Maybe. Or, maybe not. Maybe a mix of real and imagined. Why do we have to settle the question right now?
However, sometimes there may be cases where HD is measured at a very low number and for unknown reasons, with music there is some small audible effect. Some people immediately conclude the only possible explanations are that someone is lying, or someone is imagining things.
My opinion is that sometimes there are things going on that are producing more audible effects than we are expecting from the measurements we make. IMD is one of the possibilities, but not the only one. We know there can also be what we may refer to as nonstationary nonlinearities. Thermal distortion would be one of those.
Some dacs, such as sigma-delta can have some very complex things going on in them that we rarely test for, that Stereophile does not test for either. Yet they exist. State variable settling can be one of those.
In addition to whatever some complex piece of electronics is doing, the human brain is also doing its thing. Sometimes the exact line between a perception that is real and that is imagined is very blurred and hard to pick apart. That we can see yellow from only green and blue is one effect that is pretty well understood and that most people experience so we think nothing of it. When only some people report an audible perceptual experience from a piece of complex electronics we may at first think they must be lying or crazy. Maybe. Or, maybe not. Maybe a mix of real and imagined. Why do we have to settle the question right now?
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Here are some measurements (and comments) of the Chord Mojo DAC from Audio Science Review:
Chord Mojo DAC at Audio Science Review
Chord Mojo DAC at Audio Science Review
I think people get suspicious when large amounts of money are required in some way, I think that's reasonable. I know for a fact that many people lie, imagine stuff, tell stories, look for meaning in coincidence habitually most of the time. So what? If this is news to anyone, where have you been?
That’s incorrect, ridiculous and also a cop out.
There’s many hearing tests of type and scope.
Alternatively, set up your own test if you are unsatisfied with the options, and post it here.
Presumably if no one is willing to even release a basic hearing test; any kind of complex test will likely reveal additional limitations not allude to the presence of some brain DSP x-factor allowing one to hear such minute variances.
Again, there seems to be a moratorium on ANY hearing test from audio golden ears. Nothing. Nada. Zilch.
If they are so confident in their abilities, then they should be able to find a method of convincing us of its plausibility, starting with a rudimentary wel-established testing protocol.
Mark, perhaps a disclosure as to what your financial interests are in the game will lend credence to your tired argument.
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When you delve into how hearing works it's amazing how little is known about exactly how the nerve impulses are encoded and decoded by the ear and brain
Judging by how conversations go here, it would seem to point to whatever brain DSP everyone has left is likely malfunctioning across the board.
Can half of you remember where your keys are? Response time is reduced. Cognitive function across the board is impaired. Remember what the age is of the average audio consumer. 5 year old kids aren’t buying 14k DACs.
Can half of you remember where your keys are? Response time is reduced. Cognitive function across the board is impaired. Remember what the age is of the average audio consumer. 5 year old kids aren’t buying 14k DACs.
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Are you forgetting how many people here are most likely high functioning autistic?
And that small audible effect in a difference file goes to linear differences (amplitude and phase) completely.
Mark, I have a test for you. Would you, or anyone else, be willing to download this file
http://pmacura.cz/sig_diff.zip
unzip and listen? It is stereo and should be listened as stereo, with headphones optimally, or speakers as an option, but sitting in your listening position. Play the file and then tell me what you hear from your right ear or right speaker. It would be a total silence, I guess. However, there is not a silence. I would tell later what is there, to prevent strange explanations. The necessary condition is that your audio gear has crosstalk better than 70dB. It is also a good test of swapped channels
.There is a big difference between listening for a harmonic distortion artifact at -130 dB and a non harmonically related signal 130 dB below another noise source. If you ever look at the noise spectrum outdoors at low frequencies you will quickly grasp why human hearing has a functional and practical low frequency limit. Making measurements outdoors wind is not the only issue, lightning has massive low frequency content that travels miles and will show up in measurements well before it gets close enough to perceive.
Now in a practical circuit I would be curious as to the measurement technique which yields those results. Averaging of the measurement would reduce the measured noise level, but that is not the same as the perceived level!
As to the standard medical hearing test it is level threshold at octave band frequencies only up to 8,000 hertz. The more precise test using continually variable frequency threshold is not used anywhere near as often in the U.S.
Pavel can I remind you of the technique to build into a test a bit of self verification?
Now in a practical circuit I would be curious as to the measurement technique which yields those results. Averaging of the measurement would reduce the measured noise level, but that is not the same as the perceived level!
As to the standard medical hearing test it is level threshold at octave band frequencies only up to 8,000 hertz. The more precise test using continually variable frequency threshold is not used anywhere near as often in the U.S.
Pavel can I remind you of the technique to build into a test a bit of self verification?
Absolutely no financial interests at all. I am comfortably retired and need nothing. I help people mod dacs for free in another thread so people can have access to high quality dacs at the lowest possible cost.
The main reason I am hesitant to suspect people are lying or crazy is because I have a fair amount of hearing loss. Can't hear high frequencies any more. However, I am still pretty good at hearing distortion in the frequency range I can still hear. That probably comes from some natural dislike of distortion, several years work as doing live sound shortly after college, and working on mixing records for fun for quite a few years while I did other things for a living. If I can still hear pretty low level distortion, so can others, and probably better than I can.
I also know other people that didn't used to be able to hear distortion well, but who have become much better at it. Seems to me it is a skill most people have to learn, as is relative pitch and a good sense of time, both of which are needed for performing music. People learn to hear time and rhythm, usually with training and always with practice, much as they can learn to hear distortion.
However, I also have studied in other fields too and know quite well that human brains have many known biases. What Scott called sighted listening is one, but so is detecting liars and cheats. Some people have lower alarm thresholds than others for deciding someone is cheat. There can be false positives and false negatives in that judgement. The more I learn, the more I tend to defer judgement of others. Fact is most people are some mix of good and bad, and all humans lie at times. That's what the research shows.
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